Abstract:
Unlike linear car-following models, nonlinear models generally can produce more realistic traffic oscillation phenomenon (i.e., stop-and-go traffic), but nonlinearity makes analytical quantification of oscillation characteristics (e.g., periodicity and amplitude) significantly more difficult. In this talk, we present a mathematical framework that builds upon the describing function technique from nonlinear control theory to accurately quantify oscillation characteristics for a general class of nonlinear car-following laws. We also propose a set of new measures on steady-state traffic properties and oscillation characteristics and systematically apply them to validate the describing function approach (DFA) based on field vehicle trajectory data. The analytical DFA predictions of oscillation propagation patterns under the calibrated car-following law are then compared with (i) the measured oscillation properties from field data and (ii) the simulated oscillation characteristics under the same car-following law. Empirical experiments show that the prediction, the simulation, and the field observation match quite nicely. This not only validates the analytical DFA prediction approach, but also shows that the proposed framework is capable of calibrating a realistic nonlinear car-following law that reproduces the observed oscillation propagation phenomenon. The research outcome not only deepens our understanding of the traffic oscillation phenomenon but also paves the foundation for design and calibration of realistic traffic control strategies that can be used to mitigate traffic oscillations.

(Joint work with Ph.D. students Xiaopeng Li and Xin Wang)

Biography:
Yanfeng Ouyang is an associate professor and the Paul F. Kent Endowed Faculty Scholar of Civil and Environmental Engineering at the University of Illinois at Urbana-Champaign (UIUC). He also holds a courtesy appointment in the Department of Industrial and Enterprise Systems Engineering at UIUC. He received his Ph.D. in civil engineering from the University of California at Berkeley in 2005. His research mainly lies in the areas of transportation systems analysis, logistics systems design, and network optimization. He currently serves on the editorial advisory board of Transportation Research Part B and the Journal of Infrastructure Systems. He is the chair of Transportation Research Board's Subcommittee on Transit, Freight and Logistics, and the chair of the Freight Logistics Special Interest Group of the INFORMS Transportation Science and Logistics Society. He received the Faculty Early Career Development (CAREER) Award from the U.S. National Science Foundation in 2008, the Xerox Award for Faculty Research from UIUC in 2010, and the Gordon F. Newell Award from the University of California at Berkeley in 2005.